December 18, 2014

When I replaced my aging torchdown roof with a new “cool” roof (white PVC membrane to reflect heat), I did so hoping to keep the house more comfortable in summer heat, and avoid having to install air conditioning, a known energy hog. But honestly I’ve had no real way of measuring the success of the investment, other than simply confirming that in the summers since, I haven’t needed AC.

But with my solar panels, I can get hard data, and lots of it, from multiple sources.

Enphase Energy, which provided the microinverters for my array, has a website that allows me real-time and historical performance data in monthly, daily, and even hourly views. If any of my 20 microinverters is malfunctioning, the site lets me know and specifies which one so the installer can fix the problem more efficiently.

The Enphase web-based tool shows how much power my array is producing every day. The better the production the lighter the box color. This shows that my best day so far came early on, with 14.1 kWh on October 19.

And if I forget to check the site for this information, Enphase bails me out by sending me a monthly summary email anyway.

As for Puget Sound Energy, the utility not only installed new digital meters when my panels went up, but they also familiarized me with how to read the pertinent information from the meters, and have included solar performance data on my monthly bills.

This level of feedback about my solar investment instills confidence that solar installers, the solar industry, and utilities are treating renewable energy as a viable, measureable option for consumers to consider on its merits. The numbers don’t always make me happy (I’m looking at you, November 28). But I’m grateful that this is one home improvement I can always assess accurately.